Various mobile telecommunication standards include specifications for a subscriber service known in the art as short message service (SMS) (otherwise known as cellular message teleservice, text messaging, PCS messaging, and a variety of other names) which provides for the transmission of short text messages to a subscriber at her or his mobile terminal. For example, the existing IS-136 TDMA Standard describes a one-way messaging service that allows text of 180 characters or less to be sent by a short message service center (SMSC) to an IS-136 capable mobile phone. In the current implementation of the service, the originator of the text message receives no verification that the recipient's phone ever received the message.
Nevertheless, numerous technologies have been developed which allow for confirmation of whether a message has been delivered to a subscriber terminal. Existing services based on SMS fall into one of three categories: (1) There are two-way paging systems wherein the paging subscriber can initiate a manual response to a message, which often requires new devices or new interfaces on cell phones. (2) Some systems provide a unique confirmation number to each message and the sender can call the system later to track the delivery status of a message using the confirmation code. (3) There are enhanced protocols being proposed to enable advanced wireless information services including confirmed message delivery, an example being the ReFLEX system of MOTOROLA. However, such protocols are not in widespread use.
Accordingly, a network-assisted system that uses existing protocol standards, that does not require recipients to manually acknowledge receipt of each message, or that does not require the sender to repeatedly check message delivery status would be beneficial.